This invention relates to hitch assemblies for coupling trailing vehicles to pulling vehicles and, more particularly, to a hitch assembly having a probe member on one vehicle and a guide member on the other vehicle for receipt of the probe member in order to couple the trailing vehicle with respect to the pulling vehicle.
The manual coupling and uncoupling of a trailing vehicle to and from a pulling vehicle is dangerous and inconvenient. The vehicles are usually large, making visual line-up of the relatively small hitch assemblies difficult and often dependent upon trial and error attempts, especially when the driver of the pulling vehicle is alone. The driver must line up the vehicles as close as he can, get out of the pulling vehicle, and go to the hitch assembly in hopes that the respective hitch components are in close enough proximity for coupling. When a second person is available, the second person must be close enough to line up the hitch components. Whether it be the driver or a second person between the two vehicles, this is an inherently dangerous situation. Furthermore, it is neither time nor cost efficient for trial and error coupling with repeated trips by the driver from the pulling vehicle to the hitch assembly and back again. Likewise, it is neither time nor cost efficient for two people to couple and uncouple the vehicles.
Accordingly, it is desirable to provide a hitch assembly which will automatically raise, position, couple and uncouple a tongue portion of a trailing vehicle with respect to a drawbar portion of a pulling vehicle while the driver of the pulling vehicle remains in the pulling vehicle. It is also desirable to provide a hitch assembly which can be visually lined up from the driver's seat of the pulling vehicle. Moreover, conditions of the terrain as well as the relative elevations, space and angle of approach between a pulling vehicle and a trailing vehicle vary greatly so that any automatic hitch assembly must be versatile in these respects. Of course, it is also desirable that the automatic hitch assembly be capable of attachment to existing equipment without modifications to the existing equipment.
A number of attempts have been made to provide automatic hitch assemblies. These hitch assemblies usually have some type of system to guide the tongue portion of the trailing vehicle to the drawbar portion of the pulling vehicle where the vehicles are automatically coupled.
U.S. Pat. No. 2,904,348 discloses a tongue portion of a trailer having a V-shaped, transverse, upstanding rod member which is engageable with an extending guide rod on the drawbar portion of a tractor. However, the V-shaped rod shown in this patent is fixed in position relative to the tongue portion of the trailer. Accordingly, once the extending guide rod is engaged with the upstanding V-shaped rod and the tractor and trailer are coupled, the guide rod and the V-shaped rod remain in contact thus interfering with tight turns and the like. Furthermore, the upright V-shaped rod requires the angle of approach by the tractor to the trailer to be fairly small as the upright V is easy to miss, especially at a sharp angle. Moreover, the device shown in this reference requires the tongue portion of the trailer to be raised from the ground to be lowered by the extending guide rod. Accordingly, this device will not raise a tongue portion of a trailer from the ground. This problem is compounded in certain terrains where the tongue portion of the trailer may be downhill or in a depression so as to actually be below the extending guide rod making it impossible to position the tongue portion of the trailer for automatic coupling with the drawbar portion of the tractor.
Likewise, none of the other prior art devices disclose an automatic hitch assembly wherein a V-shaped guide receives an extending rod in such a manner that the V-shaped guide is in a horizontal orientation rather than a vertical orientation which would increase the possible angle of approach by the pulling vehicle to the trailing vehicle and wherein the V-shaped guide is not in contact with the extending rod after the vehicles are coupled to avoid interference with tight turns and the like.
The difficulties in the prior art hitch assemblies are substantially eliminated by the present invention.